1. Field of the Invention
The invention relates to the use of dopamine receptor antagonists in palliative tumor therapy, particularly as agents for antagonizing side effects such as are frequently observed in tumor therapy by means of alkylphosphocholines, particularly miltefosine.
2. Background Information
It is known and described that the alkylphosphocholine miltefosine causes side effects in patients during the treatment of cancer. These also manifest themselves in patients treated with miltefosine by a marked loss of body weight (Eur. J. Cancer, Vol. 29 A, No. 2, pp. 208-209, 1993). Further side effects of the chemotherapy are: damage to the tissue with a high proliferation rate, leuko- and thrombopenia, decrease in erythrocytes, gastrointestinal disorders, loss of appetite, upper abdominal complaints, disturbed absorption and diarrhea, as well as loss of hair and also liver damage and hyperuricaemia.
In a dose-finding study by J. Verweij et al. (J. Cancer Res. Clin. Oncol 118:606-608 (1992)), it was observed that most antiemetics (including 5HT3 antagonists) were inactive in the prevention of vomiting and nausea. The smallest emetic effect was achieved if miltefosine was taken immediately after eating, domperidone being given 0.5 hours before eating in a dose of 20 mg. In the phase II studies of the same author which were carried out later (Eur. J. Cancer Vol. 29 A, No. 5 p. 779(1993), it was meanwhile found that it was not possible to prevent vomiting either by standard antiemetics or by 5HT3 antagonists.
Since the loss of weight under tumor treatment with alkylphosphocholines leads to a further weakening of the already overloaded body, it was the object of the invention to characterize substances which, in combination with miltefosine or its derivatives, antagonize the known side effects of the alkylphosphocholines such as decrease in body weight.
It must be ensured here that the anti-tumor action of miltefosine or its derivatives is not abolished or reduced by combination with the antidote and no additional side effects occur due to the administration of the combination.
The above object has now been achieved in that agents for antagonizing side effects such as are frequently observed during tumor therapy by means of alkylphosphocholines, in particular miltefosine, have been found and prepared. These are dopamine receptor antagonists, particularly the two dopamine antagonists domperidone and pimozide. It is to be understood that these agents can be administered both in a fixed combination with the alkylphosphocholine and, in each case, in individual packs and sequentially.